{

static bool quirkChecked, quirkEnabled;

if(!quirkChecked) {

const char *ident = (const char*)glGetString(GL_VENDOR);

if(ident != NULL) {

quirkChecked = true;

quirkEnabled = !strcmp(ident, "Intel Open Source Technology Center");

}

}

return quirkEnabled;

{

static bool quirkChecked, quirkEnabled;

if(!quirkChecked) {

const char *ident = (const char*)glGetString(GL_VERSION);

if(ident != NULL) {

quirkChecked = true;

quirkEnabled = !strcmp(ident, "1.1.0");

}

}

return quirkEnabled;

if(HasIntelThinLineQuirk() && width < 1.6)

width = 1.6;

glLineWidth((GLfloat)width);

switch(layer) {

case Canvas::Layer::NORMAL:

case Canvas::Layer::FRONT:

case Canvas::Layer::BACK:

glDepthFunc(GL_LEQUAL);

glDepthMask(GL_TRUE);

glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);

break;

case Canvas::Layer::DEPTH_ONLY:

glDepthFunc(GL_LEQUAL);

glDepthMask(GL_TRUE);

glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);

break;

case Canvas::Layer::OCCLUDED:

glDepthFunc(GL_GREATER);

glDepthMask(GL_FALSE);

glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);

break;

}

switch(layer) {

case Canvas::Layer::FRONT:

glDepthRange(0.0, 0.0);

break;

case Canvas::Layer::BACK:

glDepthRange(1.0, 1.0);

break;

case Canvas::Layer::NORMAL:

case Canvas::Layer::DEPTH_ONLY:

case Canvas::Layer::OCCLUDED:

// The size of this step depends on the resolution of the Z buffer; for

// a 16-bit buffer, this should be fine.

double offset = 1.0 / (65535 * 0.8) * zIndex;

glDepthRange(0.1 - offset, 1.0 - offset);

break;

}

static bool Init;

static GLubyte MaskA[(32*32)/8];

static GLubyte MaskB[(32*32)/8];

if(!Init) {

int x, y;

for(x = 0; x < 32; x++) {

for(y = 0; y < 32; y++) {

int i = y*4 + x/8, b = x % 8;

int ym = y % 4, xm = x % 4;

for(int k = 0; k < 2; k++) {

if(xm >= 1 && xm <= 2 && ym >= 1 && ym <= 2) {

(k == 0 ? MaskB : MaskA)[i] |= (0x80 >> b);

}

ym = (ym + 2) % 4; xm = (xm + 2) % 4;

}

}

}

Init = true;

}

switch(pattern) {

case Canvas::FillPattern::SOLID:

glDisable(GL_POLYGON_STIPPLE);

break;

case Canvas::FillPattern::CHECKERED_A:

glEnable(GL_POLYGON_STIPPLE);

glPolygonStipple(MaskA);

break;

case Canvas::FillPattern::CHECKERED_B:

glEnable(GL_POLYGON_STIPPLE);

glPolygonStipple(MaskB);

break;

}

Camera camera;

Lighting lighting;

// Cached OpenGL state.

struct {

bool drawing;

GLenum mode;

hStroke hcs;

Stroke *stroke;

hFill hcf;

Fill *fill;

std::weak_ptr<const Pixmap> texture;

} current;

// List-initialize current to work around MSVC bug 746973.

OpenGl1Renderer() : camera(), lighting(), current({}) {}

const Camera &GetCamera() const override { return camera; }

void DrawLine(const Vector &a, const Vector &b, hStroke hcs) override;

void DrawEdges(const SEdgeList &el, hStroke hcs) override;

bool DrawBeziers(const SBezierList &bl, hStroke hcs) override { return false; }

void DrawOutlines(const SOutlineList &ol, hStroke hcs, DrawOutlinesAs drawAs) override;

void DrawVectorText(const std::string &text, double height,

const Vector &o, const Vector &u, const Vector &v,

hStroke hcs) override;

void DrawQuad(const Vector &a, const Vector &b, const Vector &c, const Vector &d,

hFill hcf) override;

void DrawPoint(const Vector &o, hStroke hcs) override;

void DrawPolygon(const SPolygon &p, hFill hcf) override;

void DrawMesh(const SMesh &m, hFill hcfFront, hFill hcfBack) override;

void DrawFaces(const SMesh &m, const std::vector<uint32_t> &faces, hFill hcf) override;

void DrawPixmap(std::shared_ptr<const Pixmap> pm,

const Vector &o, const Vector &u, const Vector &v,

const Point2d &ta, const Point2d &tb, hFill hcf) override;

void InvalidatePixmap(std::shared_ptr<const Pixmap> pm) override;

void SelectPrimitive(unsigned mode);

void UnSelectPrimitive();

Stroke *SelectStroke(hStroke hcs);

Fill *SelectFill(hFill hcf);

void SelectTexture(std::shared_ptr<const Pixmap> pm);

void DoFatLineEndcap(const Vector &p, const Vector &u, const Vector &v);

void DoFatLine(const Vector &a, const Vector &b, double width);

void DoLine(const Vector &a, const Vector &b, hStroke hcs);

void DoPoint(Vector p, double radius);

void DoStippledLine(const Vector &a, const Vector &b, hStroke hcs, double phase = 0.0);

void UpdateProjection();

void SetCamera(const Camera &camera) override;

void SetLighting(const Lighting &lighting) override;

void StartFrame() override;

void FlushFrame() override;

void FinishFrame() override;

std::shared_ptr<Pixmap> ReadFrame() override;

void GetIdent(const char **vendor, const char **renderer, const char **version) override;

if(current.drawing && current.mode == mode) {

return;

} else if(current.drawing) {

glEnd();

}

glBegin(mode);

current.drawing = true;

current.mode = mode;

if(!current.drawing) return;

glEnd();

current.drawing = false;

{

for(int i = 0; i < 31; i++) {

int vt = (1 << i);

if(vt >= v) {

return vt;

}

}

return 0;

if(current.texture.lock() == pm) return;

glBindTexture(GL_TEXTURE_2D, 1);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

GLenum format = 0;

switch(pm->format) {

case Pixmap::Format::RGBA: format = GL_RGBA; break;

case Pixmap::Format::RGB: format = GL_RGB; break;

case Pixmap::Format::A: format = GL_ALPHA; break;

case Pixmap::Format::BGRA:

case Pixmap::Format::BGR:

ssassert(false, "Unexpected pixmap format");

}

if(!HasGl1V1Quirk()) {

glTexImage2D(GL_TEXTURE_2D, 0, format, pm->width, pm->height, 0,

format, GL_UNSIGNED_BYTE, &pm->data[0]);

} else {

GLsizei width = RoundUpToPowerOfTwo(pm->width);

GLsizei height = RoundUpToPowerOfTwo(pm->height);

glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0,

format, GL_UNSIGNED_BYTE, 0);

glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, pm->width, pm->height,

format, GL_UNSIGNED_BYTE, &pm->data[0]);

}

glEnable(GL_TEXTURE_2D);

current.texture = pm;

// A table of cos and sin of (pi*i/10 + pi/2), as i goes from 0 to 10

static const double Circle[11][2] = {

{ 0.0000, 1.0000 },

{ -0.3090, 0.9511 },

{ -0.5878, 0.8090 },

{ -0.8090, 0.5878 },

{ -0.9511, 0.3090 },

{ -1.0000, 0.0000 },

{ -0.9511, -0.3090 },

{ -0.8090, -0.5878 },

{ -0.5878, -0.8090 },

{ -0.3090, -0.9511 },

{ 0.0000, -1.0000 },

};

SelectPrimitive(GL_TRIANGLE_FAN);

for(auto pc : Circle) {

double c = pc[0], s = pc[1];

ssglVertex3v(p.Plus(u.ScaledBy(c)).Plus(v.ScaledBy(s)));

}

UnSelectPrimitive();

// The half-width of the line we're drawing.

double hw = width / 2;

Vector ab = b.Minus(a);

Vector gn = (camera.projRight).Cross(camera.projUp);

Vector abn = (ab.Cross(gn)).WithMagnitude(1);

abn = abn.Minus(gn.ScaledBy(gn.Dot(abn)));

// So now abn is normal to the projection of ab into the screen, so the

// line will always have constant thickness as the view is rotated.

abn = abn.WithMagnitude(hw);

ab = gn.Cross(abn);

ab = ab. WithMagnitude(hw);

// The body of a line is a quad

SelectPrimitive(GL_QUADS);

ssglVertex3v(a.Plus (abn));

ssglVertex3v(b.Plus (abn));

ssglVertex3v(b.Minus(abn));

ssglVertex3v(a.Minus(abn));

// And the line has two semi-circular end caps.

DoFatLineEndcap(a, ab, abn);

DoFatLineEndcap(b, ab.ScaledBy(-1), abn);

if(a.Equals(b)) return;

Stroke *stroke = SelectStroke(hcs);

if(stroke->WidthPx(camera) <= 3.0) {

SelectPrimitive(GL_LINES);

ssglVertex3v(a);

ssglVertex3v(b);

} else {

DoFatLine(a, b, stroke->WidthPx(camera) / camera.scale);

}

if(d <= 3.0) {

Vector u = camera.projRight.WithMagnitude(d / 2.0 / camera.scale);

SelectPrimitive(GL_LINES);

ssglVertex3v(p.Minus(u));

ssglVertex3v(p.Plus(u));

} else {

Vector u = camera.projRight.WithMagnitude(d / 2.0 / camera.scale);

Vector v = camera.projUp.WithMagnitude(d / 2.0 / camera.scale);

DoFatLineEndcap(p, u, v);

DoFatLineEndcap(p, u.ScaledBy(-1.0), v);

}

Stroke *stroke = SelectStroke(hcs);

if(stroke->stipplePattern == StipplePattern::CONTINUOUS) {

DoLine(a, b, hcs);

return;

}

double scale = stroke->StippleScaleMm(camera);

const std::vector<double> &dashes = StipplePatternDashes(stroke->stipplePattern);

double length = StipplePatternLength(stroke->stipplePattern) * scale;

phase -= floor(phase / length) * length;

double curPhase = 0.0;

size_t curDash;

for(curDash = 0; curDash < dashes.size(); curDash++) {

curPhase += dashes[curDash] * scale;

if(phase < curPhase) break;

}

Vector dir = b.Minus(a);

double len = dir.Magnitude();

dir = dir.WithMagnitude(1.0);

double cur = 0.0;

Vector curPos = a;

double width = stroke->WidthMm(camera);

double curDashLen = (curPhase - phase) / scale;

while(cur < len) {

double next = std::min(len, cur + curDashLen * scale);

Vector nextPos = curPos.Plus(dir.ScaledBy(next - cur));

if(curDash % 2 == 0) {

if(curDashLen <= LENGTH_EPS) {

DoPoint(curPos, width);

} else {

DoLine(curPos, nextPos, hcs);

}

}

cur = next;

curPos = nextPos;

curDash++;

curDashLen = dashes[curDash % dashes.size()];

}

double phase = 0.0;

for(const SEdge *e = el.l.First(); e; e = el.l.NextAfter(e)) {

DoStippledLine(e->a, e->b, hcs, phase);

phase += e->a.Minus(e->b).Magnitude();

}

Vector projDir = camera.projRight.Cross(camera.projUp);

double phase = 0.0;

switch(drawAs) {

case DrawOutlinesAs::EMPHASIZED_AND_CONTOUR:

for(const SOutline &o : ol.l) {

if(o.IsVisible(projDir) || o.tag != 0) {

DoStippledLine(o.a, o.b, hcs, phase);

}

phase += o.a.Minus(o.b).Magnitude();

}

break;

case DrawOutlinesAs::EMPHASIZED_WITHOUT_CONTOUR:

for(const SOutline &o : ol.l) {

if(!o.IsVisible(projDir) && o.tag != 0) {

DoStippledLine(o.a, o.b, hcs, phase);

}

phase += o.a.Minus(o.b).Magnitude();

}

break;

case DrawOutlinesAs::CONTOUR_ONLY:

for(const SOutline &o : ol.l) {

if(o.IsVisible(projDir)) {

DoStippledLine(o.a, o.b, hcs, phase);

}

phase += o.a.Minus(o.b).Magnitude();

}

break;

}

const Vector &o, const Vector &u, const Vector &v,

hStroke hcs) {

auto traceEdge = [&](Vector a, Vector b) { DoStippledLine(a, b, hcs); };

VectorFont::Builtin()->Trace(height, o, u, v, text, traceEdge, camera);

hFill hcf) {

SelectFill(hcf);

SelectPrimitive(GL_QUADS);

ssglVertex3v(a);

ssglVertex3v(b);

ssglVertex3v(c);

ssglVertex3v(d);

Stroke *stroke = SelectStroke(hcs);

Canvas::Fill fill = {};

fill.layer = stroke->layer;

fill.zIndex = stroke->zIndex;

fill.color = stroke->color;

hFill hcf = GetFill(fill);

Vector r = camera.projRight.ScaledBy(stroke->width/2.0/camera.scale);

Vector u = camera.projUp.ScaledBy(stroke->width/2.0/camera.scale);

Vector a = o.Plus (r).Plus (u),

b = o.Plus (r).Minus(u),

c = o.Minus(r).Minus(u),

d = o.Minus(r).Plus (u);

DrawQuad(a, b, c, d, hcf);

float weight[4], void **outData) {

Vector *n = (Vector *)AllocTemporary(sizeof(Vector));

n->x = coords[0];

n->y = coords[1];

n->z = coords[2];

*outData = n;

UnSelectPrimitive();

SelectFill(hcf);

GLUtesselator *gt = gluNewTess();

gluTessCallback(gt, GLU_TESS_BEGIN, (GLUCallback) glBegin);

gluTessCallback(gt, GLU_TESS_VERTEX, (GLUCallback) Vertex);

gluTessCallback(gt, GLU_TESS_END, (GLUCallback) glEnd);

gluTessCallback(gt, GLU_TESS_COMBINE, (GLUCallback) Combine);

gluTessProperty(gt, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_ODD);

ssglNormal3v(p.normal);

gluTessNormal(gt, p.normal.x, p.normal.y, p.normal.z);

gluTessBeginPolygon(gt, NULL);

for(const SContour &sc : p.l) {

gluTessBeginContour(gt);

for(const SPoint &sp : sc.l) {

double ap[3] = { sp.p.x, sp.p.y, sp.p.z };

gluTessVertex(gt, ap, (GLvoid *) &sp.p);

}

gluTessEndContour(gt);

}

gluTessEndPolygon(gt);

gluDeleteTess(gt);

UnSelectPrimitive();

RgbaColor frontColor = {},

backColor = {};

Fill *frontFill = SelectFill(hcfFront);

frontColor = frontFill->color;

ssglMaterialRGBA(GL_FRONT, frontFill->color);

if(hcfBack.v != 0) {

Fill *backFill = fills.FindById(hcfBack);

backColor = backFill->color;

ssassert(frontFill->layer == backFill->layer &&

frontFill->zIndex == backFill->zIndex,

"frontFill and backFill should belong to the same depth range");

ssassert(frontFill->pattern == backFill->pattern,

"frontFill and backFill should have the same pattern");

glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, 1);

ssglMaterialRGBA(GL_BACK, backFill->color);

} else {

glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, 0);

}

RgbaColor triangleColor = {};

glEnable(GL_LIGHTING);

glBegin(GL_TRIANGLES);

for(const STriangle &tr : m.l) {

if(frontColor.IsEmpty() || backColor.IsEmpty()) {

if(triangleColor.IsEmpty() || !triangleColor.Equals(tr.meta.color)) {

triangleColor = tr.meta.color;

if(frontColor.IsEmpty()) {

ssglMaterialRGBA(GL_FRONT, triangleColor);

}

if(backColor.IsEmpty()) {

ssglMaterialRGBA(GL_BACK, triangleColor);

}

}

}

if(tr.an.EqualsExactly(Vector::From(0, 0, 0))) {

// Compute the normal from the vertices

ssglNormal3v(tr.Normal());

ssglVertex3v(tr.a);

ssglVertex3v(tr.b);

ssglVertex3v(tr.c);

} else {

// Use the exact normals that are specified

ssglNormal3v(tr.an);

ssglVertex3v(tr.a);

ssglNormal3v(tr.bn);

ssglVertex3v(tr.b);

ssglNormal3v(tr.cn);

ssglVertex3v(tr.c);

}

}

glEnd();

glDisable(GL_LIGHTING);

SelectFill(hcf);

SelectPrimitive(GL_TRIANGLES);

size_t facesSize = faces.size();

for(const STriangle &tr : m.l) {

uint32_t face = tr.meta.face;

for(size_t j = 0; j < facesSize; j++) {

if(faces[j] != face) continue;

ssglVertex3v(tr.a);

ssglVertex3v(tr.b);

ssglVertex3v(tr.c);

break;

}

}

const Vector &o, const Vector &u, const Vector &v,

const Point2d &ta, const Point2d &tb, hFill hcf) {

double xfactor = 1.0,

yfactor = 1.0;

if(HasGl1V1Quirk()) {

xfactor = (double)pm->width / RoundUpToPowerOfTwo(pm->width);

yfactor = (double)pm->height / RoundUpToPowerOfTwo(pm->height);

}

UnSelectPrimitive();

SelectFill(hcf);

SelectTexture(pm);

SelectPrimitive(GL_QUADS);

glTexCoord2d(ta.x * xfactor, ta.y * yfactor);

ssglVertex3v(o);

glTexCoord2d(ta.x * xfactor, tb.y * yfactor);

ssglVertex3v(o.Plus(v));

glTexCoord2d(tb.x * xfactor, tb.y * yfactor);

ssglVertex3v(o.Plus(u).Plus(v));

glTexCoord2d(tb.x * xfactor, ta.y * yfactor);

ssglVertex3v(o.Plus(u));

if(current.texture.lock() == pm) {

current.texture.reset();

}

UnSelectPrimitive();

glViewport(0, 0,

(GLsizei)(camera.width * camera.pixelRatio),

(GLsizei)(camera.height * camera.pixelRatio));

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

glScaled(camera.scale * 2.0 / camera.width,

camera.scale * 2.0 / camera.height,

camera.scale * 1.0 / 30000);

double mat[16];

// Last thing before display is to apply the perspective

double clp = camera.tangent * camera.scale;

MakeMatrix(mat, 1, 0, 0, 0,

0, 1, 0, 0,

0, 0, 1, 0,

0, 0, clp, 1);

glMultMatrixd(mat);

// Before that, we apply the rotation

Vector projRight = camera.projRight,

projUp = camera.projUp,

n = camera.projUp.Cross(camera.projRight);

MakeMatrix(mat, projRight.x, projRight.y, projRight.z, 0,

projUp.x, projUp.y, projUp.z, 0,

n.x, n.y, n.z, 0,

0, 0, 0, 1);

glMultMatrixd(mat);

// And before that, the translation

Vector offset = camera.offset;

MakeMatrix(mat, 1, 0, 0, offset.x,

0, 1, 0, offset.y,

0, 0, 1, offset.z,

0, 0, 0, 1);

glMultMatrixd(mat);

glMatrixMode(GL_MODELVIEW);

glLoadIdentity();

glClearDepth(1.0);

glClear(GL_DEPTH_BUFFER_BIT);

glEnable(GL_NORMALIZE);

glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

glEnable(GL_BLEND);

glEnable(GL_LINE_SMOOTH);

glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);

// don't enable GL_POLYGON_SMOOTH; that looks ugly on some graphics cards,

// drawn with leaks in the mesh

glDepthFunc(GL_LEQUAL);

glEnable(GL_DEPTH_TEST);

if(EXACT(lighting.lightIntensity[0] != 0.0)) {

glEnable(GL_LIGHT0);

GLfloat f = (GLfloat)lighting.lightIntensity[0];

GLfloat li0[] = { f, f, f, 1.0f };

glLightfv(GL_LIGHT0, GL_DIFFUSE, li0);

glLightfv(GL_LIGHT0, GL_SPECULAR, li0);

Vector ld = camera.VectorFromProjs(lighting.lightDirection[0]);

GLfloat ld0[4] = { (GLfloat)ld.x, (GLfloat)ld.y, (GLfloat)ld.z, 0 };

glLightfv(GL_LIGHT0, GL_POSITION, ld0);

}

if(EXACT(lighting.lightIntensity[1] != 0.0)) {

glEnable(GL_LIGHT1);

GLfloat f = (GLfloat)lighting.lightIntensity[1];

GLfloat li0[] = { f, f, f, 1.0f };

glLightfv(GL_LIGHT1, GL_DIFFUSE, li0);

glLightfv(GL_LIGHT1, GL_SPECULAR, li0);

Vector ld = camera.VectorFromProjs(lighting.lightDirection[1]);

GLfloat ld0[4] = { (GLfloat)ld.x, (GLfloat)ld.y, (GLfloat)ld.z, 0 };

glLightfv(GL_LIGHT1, GL_POSITION, ld0);

}

if(EXACT(lighting.ambientIntensity != 0.0)) {

GLfloat ambient[4] = { (float)lighting.ambientIntensity,

(float)lighting.ambientIntensity,

(float)lighting.ambientIntensity, 1 };

glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambient);

}

glClearColor(lighting.backgroundColor.redF(), lighting.backgroundColor.greenF(),

lighting.backgroundColor.blueF(), lighting.backgroundColor.alphaF());

glClear(GL_COLOR_BUFFER_BIT);

glClearDepth(1.0);

glClear(GL_DEPTH_BUFFER_BIT);

UnSelectPrimitive();

glFlush();

glFinish();

GLenum error = glGetError();

if(error != GL_NO_ERROR) {

dbp("glGetError() == 0x%X %s", error, gluErrorString(error));

}

int width = (int)(camera.width * camera.pixelRatio);

int height = (int)(camera.height * camera.pixelRatio);

std::shared_ptr<Pixmap> pixmap =

Pixmap::Create(Pixmap::Format::RGB, (size_t)width, (size_t)height);

glReadPixels(0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, &pixmap->data[0]);

ssassert(glGetError() == GL_NO_ERROR, "Unexpected glReadPixels error");

return pixmap;

*vendor = (const char *)glGetString(GL_VENDOR);

*renderer = (const char *)glGetString(GL_RENDERER);

*version = (const char *)glGetString(GL_VERSION);